The broad objective of this project is to understand characteristics of behavior which may contribute to the pathogenesis of coronary artery disease. This objective is being accomplished by pursuing two related lines of research. The first research direction examines patterns of responding (reaction time and intellectual test performance) as a function of a) magnitude of angiographically documented disease, and b) presence of a so-called "Type A" coronary-prone behavior pattern (which has been associated with increased incidence and prevalence of coronary disease). Previous research suggests that both patients with clinical coronary disease and symptom-free Type A subjects may exhibit impaired performance. To examine behavioral, attitudinal, and physiological mechanisms which may be involved in impaired performance, several studies are being conducted to examine the source of this alleged psychomotor slowing. A second line of research being pursued concerns the possible relationship of various components of "Type A" to angiographically documented disease. This investigation is based on findings that Pattern A is composed of several separable and discriminable dimensions and that particular aspects of this behavior pattern may be most strongly related to pathogenesis of disease.